CN101224745A - hybrid car - Google Patents

Abstract

The invention relates to a hybrid vehicle with an internal combustion engine (2) and an electric machine. A hybrid vehicle has a tank venting system comprising at least one fuel tank (7) and an intake line (5) leading from a regenerative filter device (6) to an intake line (3) of an internal combustion engine (2). In addition, a control device (11) is provided, which can operate various valve devices (9, 9') for flushing the filter device (6), so that ambient air can pass through the filter device (6) and the suction line (5) to the internal combustion engine (2). The control device ( 11 ) is also designed in such a way that it switches the internal combustion engine ( 2 ) as a function of the load state of the filter device ( 6 ) or the flushing gas concentration when the hybrid vehicle is driven purely electrically.

Description

hybrid car

technical field

The invention relates to a hybrid vehicle with an internal combustion engine and an electric machine.

Background technique

In order to be able to comply with increasingly stringent environmental regulations, today's vehicles are often equipped with a filter unit, which is installed in the exhaust duct of the fuel tank. The filter device preferably has activated carbon as filter material for filtering hydrocarbons out of the tank exhaust gas flow, so that no or very few hydrocarbons enter the environment. However, if the filter material is saturated, it is no longer able to absorb further hydrocarbons and the filter unit loses its function. However, in order to keep the filter device functionally effective for a long time, it is necessary to clean the filter device from time to time and thereby regenerate the filter material. The purge flow for regenerating the filter material is now conveyed to the intake tract of the internal combustion engine, so that the hydrocarbons washed out of the filter material can be burned in the internal combustion engine to protect the environment. However, in motor vehicles with a hybrid drive, the problem here is that the internal combustion engine is not continuously running, but is switched off, especially in the case of a purely electric drive. But in the off state, it is not possible to burn off the hydrocarbons flushed from the filter unit into the absorber pipe, so this solution is not optimal in hybrid vehicles.

Contents of the invention

The problem addressed by the present invention is to provide an improved or at least a different embodiment, which is characterized in particular by very low emissions of harmful substances.

According to the invention, this problem is solved by the subject matter of the independent claims. Some advantageous embodiments are the subject matter of the dependent claims.

The general idea on which the invention is based is that, for a hybrid vehicle with an internal combustion engine, an electric machine and a tank venting system with a regenerative filter arrangement, a control device is provided which, when the hybrid vehicle is in purely electric drive and at the same time requires In the case of flushing or regeneration of the filter arrangement, the control unit starts the internal combustion engine and thus feeds the hydrocarbons flushed back from the filter arrangement to the internal combustion engine for combustion. The filter device is then arranged in the tank exhaust line which leads from the tank into the environment and can be closed by means of a valve device, wherein a valve device is arranged in the suction line between the filter device and an intake line of the internal combustion engine middle. If the filter material of the filter device is saturated with hydrocarbons, the control device actuates the valve device in order to flush the filter device and thus achieve the above-mentioned delivery of the hydrocarbons present in the line and in the filter device to the internal combustion engine. Of course, combustion of the hydrocarbons present in the line or in the filter arrangement is only possible at this time when the internal combustion engine is operated at least with idle gas. However, it is precisely in vehicles with hybrid drive that the internal combustion engine is switched off during electric drive. The control device is therefore designed for this purpose in such a way that it switches on or starts the internal combustion engine when the hybrid vehicle is driven electrically, depending on the load state of the filter device. Thus, when the hybrid vehicle is under electric drive and for example a sensor detects that the filter material is saturated with hydrocarbons, the control unit opens the valves in the intake line and the tank exhaust line on the one hand and starts the internal combustion engine on the other hand. , which burns the hydrocarbons fed to it. With the solution according to the invention, it is thus possible to significantly reduce the amount of hydrocarbons and thus the emission of pollutants in hybrid vehicles.

It is expedient to provide a negative pressure tank in the intake tract of the internal combustion engine, which, when the valve device is open, can flush the filter device even when the internal combustion engine is switched off. The vacuum storage tank preferably has a sufficient vacuum volume for flushing the filter arrangement and can be opened if necessary. This can also be done in the purely electric driving state of the hybrid vehicle, wherein the control device opens the valve devices in the intake line and the tank exhaust line on the one hand and connects the vacuum tank to one of the internal combustion engines on the other hand. The trachea is connected communicatively. Hydrocarbons are sucked in from the intake line and from the filter material of the filter device by the vacuum prevailing in the vacuum tank and stored in the intake manifold or the vacuum tank until the internal combustion engine is started. When the internal combustion engine is started in a later operating state, the hydrocarbons stored in the negative pressure storage tank and the intake pipe can be delivered to the internal combustion engine to carry out the combustion process. This variant allows the filter material present in the filter device to be flushed or regenerated even when the internal combustion engine is switched off.

In an advantageous development of the solution according to the invention, a valve device is arranged in the tank vent line between the filter device on the one hand and the fuel tank on the other hand, and a pump device is provided in addition, which can connect the valve Pressurizes the fuel tank when the unit is turned off. Furthermore, a sensor device is provided which can detect the hydrocarbon concentration and/or the pressure in the fuel tank. By means of these devices, a tightness check of the fuel tank can be carried out, wherein the valve device is closed and the fuel tank is pressurized by the pump device. After the pump device has been switched off, the sensor device detects the time-varying pressure drop and the leak-tightness of the tank system can be deduced from the values detected in this way. At the same time, the pressurization of the fuel tank has the great advantage that the transition of the fuel from the liquid state to the gaseous state becomes more difficult, so that the evaporation rate of the fuel is significantly slower. This makes it possible to keep the fuel under pressure in a purely electric drive and thus makes it difficult at least to remove hydrocarbons from the fuel.

Further features and advantages of the invention emerge from the subclaims, the drawings and the associated description of the drawings with reference to the drawings.

It is to be understood that the features mentioned above and those still to be explained below can be used not only in the combination specified but also in other combinations or alone without departing from the scope of the present invention.

Description of drawings

Preferred exemplary embodiments of the invention are shown in the drawings and explained in detail in the following description, wherein identical reference numbers refer to identical or similar or functionally identical components.

Shown in schematic form in the accompanying drawings:

Fig. 1 in a standard embodiment according to the fuel tank venting system of the present invention,

Figure 2 is a view as in Figure 1, but with several distinct and individually selectable components of the tank vent system,

Fig. 3 according to the torque and speed distribution of the hybrid drive device of the present invention in the state of charge of the battery,

Figure 4 The view of Figure 3, but with the fuel tank exhausted.

Detailed ways

Corresponding to FIG. 1 , a hybrid drive 1 for a hybrid vehicle, not shown otherwise, has an internal combustion engine 2 and an electric machine, also not shown. The hybrid vehicle here is preferably a full hybrid vehicle, so that it can be operated both purely with the internal combustion engine and purely with the electric machine. The internal combustion engine 2 now has an intake manifold 3 and is connected to an exhaust system 4 . The intake manifold 3 supplies the internal combustion engine 2 with a fuel-air mixture, which is combusted in the internal combustion engine 2 . The combustion products then leave the internal combustion engine 2 and enter the environment via the exhaust system 4 . In the intake pipe 3 , a suction conduit 5 leads, the other end of which is connected to a filter device 6 . The intake line 5 and the filter arrangement 6 are now part of a tank venting system which also includes the fuel tank 7 . The filter device 6 has a regenerable or flushable filter material 8 and is arranged in a fuel exhaust line 10 which leads from the fuel tank 7 to the environment and which can be closed by means of a valve device 9 . Another valve device 9' is arranged in the air intake duct 5 between the internal combustion engine 2 and the filter device 6.

The hydrocarbons evaporated from the fuel now pass through the tank vent line 10 into the filter device 6 and are prevented there by the filter material 8 , for example an activated carbon filter, from being discharged into the environment. If the filter material 8 is saturated with hydrocarbons, it needs to be flushed or regenerated, for which purpose a control device 11 is provided which actuates, ie opens, the valve devices 9, 9' as required and thus passes ambient air through the filter material 8 and the suction duct 5 are delivered to the intake pipe 3. Due to the flushing of the tank vent line 10 and the filter material 8 by ambient air, the filter material 8 is regenerated and ready for reabsorption of hydrocarbons evaporated from the fuel.

However, in the hybrid drive 1 there are operating states in which the internal combustion engine 2 is switched off and the vehicle is only driven purely electrically. In this operating state, since there is no pressure drop from the intake pipe 3 to the filter device 6, flushing of the filter device 6 is not possible, so there is the risk that once the filter material 8 is completely saturated with hydrocarbons , then the hydrocarbons can enter the environment through the fuel tank exhaust conduit 10. But in this case it should be blocked anyway. Therefore, according to the invention, the control device 11 is designed for this purpose in such a way that it starts the internal combustion engine 2 under the electric drive of the hybrid vehicle depending on the load state of the filter device 6 and can thus flush the air from the filter material 8 into the intake tract. The hydrocarbons in 3 are sent for combustion.

Furthermore, further possibilities for reducing or avoiding the introduction of hydrocarbons into the environment are indicated by letters A to H in FIG. 2 , wherein these developments can be used both selectively and collectively.

Extension plan I

In variant I, a further valve device 9" is arranged in the tank vent line 10 between the filter device 6 and the fuel tank 7. In addition, a pump device 12 is provided which is able to The fuel tank 7 is pressurized. A sensor device 13 is likewise provided, which is able to detect at least the pressure in the fuel tank 7 . By closing the valve device 9" and applying pressure to the fuel tank 7, the pressure in the fuel tank increases, thereby preventing the tendency of the fuel to evaporate and thus preventing the evaporation of hydrocarbons from the fuel or at least making it difficult for it to take place. This is difficult to form gaseous hydrocarbons. In addition, the pressure loss over time can be detected by the sensor device 13, which provides an inference of the tightness of the fuel tank 7 or the connected conduit 10. By increasing the pressure, the ingress is thus reduced The amount of gaseous hydrocarbons in the filter unit 6.

Extension II

In order to be able to better determine the loading state of the filter device 6 or the filter medium 8 receiving hydrocarbons, a fill level sensor 14 is provided which is connected to the expansion device 11 .

Extension III

The expansion device 11 can carry out a so-called priority control, which includes, for example, switching on the internal combustion engine when a high hydrocarbon load of the filter medium 8 is detected. At the same time, the adjustment of the set flushing gas volume and the suppression of certain diagnostic processes can be carried out. For example, the hydrocarbon content can be detected by means of a lambda probe and the concentration level of the tank exhaust gas can be deduced therefrom. If the mixture is rich, for example, a diagnostic procedure can be suppressed and the tank vented first.

Extension IV

In order to increase the amount of flushing gas delivered to the intake pipe 3 through the tank exhaust conduit 10, the filter material 8 and the suction conduit 5 when necessary, a pump 16 can be arranged between the valve device 9' and the filter device 6, which generates The flow of the device 6 and the flow towards the intake pipe 3. The pump 16 can then be designed, for example, as an electric pump or as a pump 16' mechanically driven by the internal combustion engine 2 via a crankshaft or a camshaft. The flushing air volume can be actively increased not only by the pump 16 but also by the pump 16 ′, wherein the use of the pump 16 in the form of a mechanical brake vacuum pump on the internal combustion engine is provided, since this pump is not required in the hybrid drive 1 or not used. The pumps 16, 16' are likewise connected in communication with the control device 11. In particular, the pumps 16, 16' have the advantage that a high flushing flow can be achieved at the high intake manifold pressures present in high-load operation.

Extension plan V

In variant V, a hydrocarbon sensor 15, for example of the type lambda probe, is arranged in the inhalation line 5 between the filter device 6 and the valve device 9' for measuring the oxygen concentration. The hydrocarbon sensor 15 can also be designed as a flame ionization detector and measure the hydrocarbon concentration in the flushing gas. The reaction time for opening the valve device 9' should thereby be reduced. By knowing the concentration of the flushing gas the valve means 9' can be controlled faster, since the effect of the flushing gas on the combustion mixture can be precalculated in the control means 11.

Extension VI

In variant VI, a measuring device 17 is arranged in the suction line 5 between the filter device 6 and the valve device 9' for measuring the mass flow, in particular for measuring the mass flow of the tank exhaust, wherein the measuring device 17 can be designed, for example, as a hot film detector. The measuring device 17 is now in particular connected to the pump 16 or 16' and the control device 11.

Extension plan VII

The speed of the hybrid vehicle is represented by curve 18 in FIGS. 3 and 4 . The torque at internal combustion engine 2 on the one hand and the electric machine torque on the other hand are represented by curves 19 and 20 . If, for example, the level sensor 14 detects a high hydrocarbon load of the filter material 8 , the torque required to drive the hybrid vehicle is shifted from the internal combustion engine 2 in the direction of the electric motor, so that the internal combustion engine 2 with the intake manifold 3 A low intake manifold pressure is operated and thus a high flushing pressure difference is set. As can be seen from Figures 3 and 4, the total torque remains constant at the transmission input. In this case it can be seen from FIG. 3 that the internal combustion engine 2 generates the torque 19 which is mainly required for driving the hybrid vehicle. The torque 20 produced by the electric machine is negative so that the electric machine can act as a generator for charging the car battery. The total torque 21 is set to approximately +100 Nm, the internal combustion engine 2 generating a torque 19 of approximately +120 Nm and the electric machine generating a torque 20 of approximately −20 Nm. In contrast, the torque distribution according to FIG. 4 between the electric machine and the internal combustion engine 2 is completely different: the internal combustion engine 2 now produces a torque 19 of approximately +25 Nm and the electric machine produces a torque 20 of approximately +75 Nm. The total torque 21 is now likewise +100 Nm, so that the speed 18 does not change between the two states in FIGS. 3 and 4 .

Extension Scheme VIII

In variant VIII, a negative pressure reservoir 22 is arranged in the intake line 3 of the internal combustion engine 2, which can also flush the filter device 6 when the internal combustion engine 2 is switched off when the valve devices 9, 9' are opened. At this time, a check valve 23 is arranged between the vacuum storage tank 22 and the intake pipe 3 to prevent uncontrolled and undesired backflow. The vacuum storage tank 22 generates the vacuum required for flushing, which vacuum is generated according to other variants, for example variant D, via the pump 16 or 16'. The vacuum tank 22 allows, as a single variant, to flush the filter device 6 with the internal combustion engine 2 switched off.

Finally, it should be pointed out again that variants I to VIII can be used not only collectively but also selectively, the combination of the following variants being important: variants IV and VI, variants V and III and variants V and VII.

Claims (9)

1. hybrid vehicle has following feature:

A) hybrid vehicle has combustion engine (2) and motor,

B) hybrid vehicle has exhaust system of oil tank, and it comprises at least one fuel tank (7) and lead to the intake guide (5) of the air inlet pipe (3) of combustion engine (2) from reproducible filter for installation (6),

C) filter for installation (6) is arranged in from fuel tank (7) and leads in the fuel tank exhaust guide (10) the environment and that can close by means of valve gear (9),

D) valve gear (9) is arranged in the intake guide (5) between filter for installation (6) and air inlet pipe (3),

E) hybrid vehicle has control setup (11), it is constructed like this, be it for washing and filtering apparatus (6) operating valve device (9 in this wise, 9 '), make ambient air pass through fuel tank exhaust guide (10), filter for installation (6) and intake guide (5) and can be transported to combustion engine (2) and thus can be with at conduit (5,10) and the hydro-carbon that exists in the filter for installation be transported in the combustion engine (2) and burn

F) control setup (11) is constructed in addition like this, makes that this control setup is connected combustion engine (2) according to the loading condition of filter for installation (6) when hybrid vehicle is motorized motions.

2. feature especially as claimed in claim 1, as to have claim 1 is a) to e) hybrid vehicle, it is characterized in that, in the air inlet pipe (3) of combustion engine (2), negative pressure storage tank (22) is set, it can realize flushing to filter for installation (6) at valve gear (9,9 ') under the pent situation of combustion engine (2) when being opened.

3. hybrid vehicle as claimed in claim 1 or 2 is characterized in that,

-between filter for installation (6) and fuel tank (7), in the fuel tank exhaust guide (10) that valve gear (9 ") is arranged on,

-being provided with pumping plant (12), it can be exerted pressure to fuel tank (7) when closing in valve gear (9 "),

-being provided with sensor device (13), it can survey the pressure in the fuel tank (7).

4. as described hybrid vehicle one of in the claim 1 to 3, it is characterized in that be provided with and control setup (11) bonded assembly level transducer (14), it can survey the loading condition of the filter for installation (6) that absorbs hydro-carbon.

5. as described hybrid vehicle one of in the claim 1 to 4, it is characterized in that,

-between valve gear (9 ') and filter for installation (6), pump (16,16 ') being set, its produces by stream filter for installation (6) and that flow towards air inlet pipe (3),

The pump (16 ') that-this pump (16,16 ') is configured to motor-drive pump (16) or is configured to mechanically be driven by combustion engine (2).

6. as described hybrid vehicle one of in the claim 1 to 5, it is characterized in that, in intake guide (5), between filter for installation (6) and valve gear (9 '), be furnished with the hydrocarbon sensor (15) that is used to measure hydrocarbon concentration.

7. hybrid vehicle as claimed in claim 6 is characterized in that, hydrocarbon sensor (15) is configured to lambda seeker or flame ionization detector.

8. as described hybrid vehicle one of in the claim 1 to 7, it is characterized in that, in intake guide (5), between filter for installation (6) and valve gear (9 '), be furnished with the measurement mechanism (17) that is used to measure mass flow.

9. hybrid vehicle as claimed in claim 8 is characterized in that, the measurement mechanism (17) that is used to measure mass flow is configured to the hotting mask detector.

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